1. The Field of the Invention
The present invention relates generally to column support structures, and more particularly, but not necessarily entirely, to reinforcing wood support pilings with composite wrapping.
2. Description of Related Art
The use of column support structures is known in the art for applications such as in utility poles, bridges, piers, and buildings. Wooden column supports are often made from logs treated with one or more preservatives such as creosote. Wooden column supports, or pilings, are often desirable since they are less expensive and readily obtainable compared to pilings made from concrete, metal or composite materials. Although the wooden support pilings are treated with a preservative, they are often subjected to rot, decomposition, damage caused by insects such as termites, or damage caused by wildlife such as woodpeckers, during the life of the piling. Typically, the damage is either an exterior area of decomposition caused by chemical or mechanical action, or internal decomposition which is enabled if the wood preservative does not penetrate the center of the piling. The internal decomposition often occurs near or slightly below the ground line. This can weaken the piling to an extent that it must be repaired or replaced. Furthermore, many of the preservatives added to the wood are toxic to the environment.
Attempts have been made in the prior art to address the problem of decomposed wood pilings, by repairing the piling while it is in place. For example, U.S. Pat. No. 5,326,410 (granted Jul. 5, 1994 to Boyles) discloses a system of reinforcing a structural support in place, by excavating the earth about the pole, applying a coating of curable resin and wrapping a plurality of layers of a fiberglass fabric around the pole. This method is expensive since a crew must transport equipment and supplies to the site of the pole, and perform the repair by hand, without the aid of wrapping machinery. Furthermore, a pole repaired on site is not as strong as a pole prepared with a filament wound covering in a shop in the manner of the present invention, since the filament wound covering can be made to radially compress the pole and would reduce or prevent decomposition and other weakening action in the first place. Radial compression of the pole increases the pole strength and prevents the pole from splitting apart.
U.S. Pat. No. 5,586,838 (granted Dec. 24, 1996 to Walsh) discloses a post for resisting deterioration which is prepared prior to installation in a pier structure. The post is prepared by wrapping mesh layers and matrix resin layers around the post to completely encapsulate the post. However, this method of wrapping the post does not increase the strength of the post as much as a filament winding process, since the filament winding process allows a radial compression force to be applied to the post by the reinforcement layer.
The prior art is thus characterized by several disadvantages that are addressed by the present invention. The present invention minimizes, and in some aspects eliminates, the above-mentioned failures, and other problems, by utilizing the methods and structural features described herein.
In view of the foregoing state of the art, it would be an advancement in the art to provide a wood support piling with a composite wrapping which is economical in design and manufacture, and which is resistant to decomposition. It would be a further advancement in the art to provide a wood support piling with a composite wrapping which provides a radial compressive force to the piling which increases the strength of the piling. It would also be an advancement in the art to provide a wood support piling with a composite wrapping which is not toxic to the environment.